An active filter achieving 43.6dBm OIP3

An active filter with a 50 Ω buffer suitable as an anti-alias filter to drive a highly linear ADC is implemented in 0.13 μm SiGe BiCMOS. This 6
^th
-order Chebyshev filter has a 3 dB cutoff frequency of 28.3 MHz and achieves 36.5 dBm OIP
₃
. Nonlinear digital equalization further improves OIP
₃
to 43.6 dBm. Measurements show 92 dB of rejection at the stopband and a gain of 49 dB. The measured in-band OIP
₃
of 43.6 dBm is 19 dB higher than previously published designs.